Book material: the bottom is thick cardboard, cover and inner pages available in thin paper or cardboard
Specifications: as customers' requirments
Composition: printed book + sound controller
On the side of the book is a box that controls the sound, integrated with the sound control switch and speaker, presses the control button, and the speaker plays the stored sound file.
The characteristics of this kind of vocal book are relatively low cost and relatively simple system; the back-mounted implantable controller has relatively high-grade and invisible sound-sounding books, but it also causes the back cover to be too thick.